1.\" Copyright (c) 1996-1999 Whistle Communications, Inc. 2.\" All rights reserved. 3.\" 4.\" Subject to the following obligations and disclaimer of warranty, use and 5.\" redistribution of this software, in source or object code forms, with or 6.\" without modifications are expressly permitted by Whistle Communications; 7.\" provided, however, that: 8.\" 1. Any and all reproductions of the source or object code must include the 9.\" copyright notice above and the following disclaimer of warranties; and 10.\" 2. No rights are granted, in any manner or form, to use Whistle 11.\" Communications, Inc. trademarks, including the mark "WHISTLE 12.\" COMMUNICATIONS" on advertising, endorsements, or otherwise except as 13.\" such appears in the above copyright notice or in the software. 14.\" 15.\" THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND 16.\" TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO 17.\" REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE, 18.\" INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF 19.\" MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. 20.\" WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY 21.\" REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS 22.\" SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE. 23.\" IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES 24.\" RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING 25.\" WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 26.\" PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR 27.\" SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY 28.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30.\" THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY 31.\" OF SUCH DAMAGE. 32.\" 33.\" Author: Archie Cobbs <archie@FreeBSD.org> 34.\" 35.\" $FreeBSD$ 36.\" $Whistle: ng_iface.8,v 1.5 1999/01/25 23:46:26 archie Exp $ 37.\" 38.Dd February 6, 2019 39.Dt NG_IFACE 4 40.Os 41.Sh NAME 42.Nm ng_iface 43.Nd interface netgraph node type 44.Sh SYNOPSIS 45.In netgraph/ng_iface.h 46.Sh DESCRIPTION 47An 48.Nm iface 49node is both a netgraph node and a system networking interface. 50When an 51.Nm iface 52node is created, a new interface appears which is accessible via 53.Xr ifconfig 8 . 54.Nm Iface 55node interfaces are named 56.Dv ng0 , 57.Dv ng1 , 58etc. 59When a node is shutdown, the corresponding interface is removed 60and the interface name becomes available for reuse by future 61.Nm iface 62nodes; new nodes always take the first unused interface. 63The node itself is assigned the same name as its interface, unless the name 64already exists, in which case the node remains unnamed. 65.Pp 66An 67.Nm iface 68node has a single hook corresponding to each supported protocol. 69Packets transmitted via the interface flow out the corresponding 70protocol-specific hook. 71Similarly, packets received on a hook appear on the interface as 72packets received into the corresponding protocol stack. 73The currently supported protocols are IP, IPv6, ATM, NATM, and NS. 74.Pp 75An 76.Nm iface 77node can be configured as a point-to-point interface or a broadcast interface. 78The configuration can only be changed when the interface is down. 79The default mode is point-to-point. 80.Pp 81.Nm Iface 82nodes support the Berkeley Packet Filter (BPF). 83.Sh HOOKS 84This node type supports the following hooks: 85.Bl -tag -width ".Va inet6" 86.It Va inet 87Transmission and reception of IP packets. 88.It Va inet6 89Transmission and reception of IPv6 packets. 90.It Va atm 91Transmission and reception of ATM packets. 92.It Va natm 93Transmission and reception of NATM packets. 94.It Va ns 95Transmission and reception of NS packets. 96.El 97.Sh CONTROL MESSAGES 98This node type supports the generic control messages, plus the following: 99.Bl -tag -width foo 100.It Dv NGM_IFACE_GET_IFNAME Pq Ic getifname 101Returns the name of the associated interface as a 102.Dv NUL Ns -terminated 103.Tn ASCII 104string. 105Normally this is the same as the name of the node. 106.It Dv NGM_IFACE_GET_IFINDEX Pq Ic getifindex 107Returns the global index of the associated interface as a 32 bit integer. 108.It Dv NGM_IFACE_POINT2POINT Pq Ic point2point 109Set the interface to point-to-point mode. 110The interface must not currently be up. 111.It Dv NGM_IFACE_BROADCAST Pq Ic broadcast 112Set the interface to broadcast mode. 113The interface must not currently be up. 114.El 115.Sh SHUTDOWN 116This node shuts down upon receipt of a 117.Dv NGM_SHUTDOWN 118control message. 119The associated interface is removed and becomes available 120for use by future 121.Nm iface 122nodes. 123.Pp 124Unlike most other node types, an 125.Nm iface 126node does 127.Em not 128go away when all hooks have been disconnected; rather, and explicit 129.Dv NGM_SHUTDOWN 130control message is required. 131.Sh ALTQ Support 132The 133.Nm 134interface supports ALTQ bandwidth management feature. 135However, 136.Nm 137is a special case, since it is not a physical interface with limited bandwidth. 138One should not turn ALTQ on 139.Nm 140if the latter corresponds to some tunneled connection, e.g.\& PPPoE or PPTP. 141In this case, ALTQ should be configured on the interface that is used to 142transmit the encapsulated packets. 143In case when your graph ends up with some kind of serial line, either 144synchronous or modem, the 145.Nm 146is the right place to turn ALTQ on. 147.Sh Nesting 148.Nm 149supports nesting, a configuration when traffic of one 150.Nm 151interface flows through the other. 152The default maximum allowed nesting level is 2. 153It can be changed at runtime setting 154.Xr sysctl 8 155variable 156.Va net.graph.iface.max_nesting 157to the desired level of nesting. 158.Sh SEE ALSO 159.Xr altq 4 , 160.Xr bpf 4 , 161.Xr netgraph 4 , 162.Xr ng_cisco 4 , 163.Xr ifconfig 8 , 164.Xr ngctl 8 165.Xr sysctl 166.Sh HISTORY 167The 168.Nm iface 169node type was implemented in 170.Fx 4.0 . 171.Sh AUTHORS 172.An Archie Cobbs Aq Mt archie@FreeBSD.org 173